The onset of puberty can be a difficult transition for our teens as they navigate physical and emotional changes in their bodies.

And it can be a tough time for parents, as we learn to adapt to our children growing older and going through a process which will take them from childhood to adolescence in just a few short years.

In recent years, a startling statistic has become evident for both parents and physicians — puberty is beginning earlier than ever before.

Physicians and scientists think they have found several viable reasons for this change and their research should put every parent on alert.

Scientific American reported:

Researchers first noticed the earlier onset of puberty in the late 1990s, and recent studies confirm the mysterious public health trend.

A 2012 analysis found that American girls exposed to high levels of common household chemicals had their first periods earlier than those with lower exposures. “This study adds to the growing body of scientific research that exposure to environmental chemicals may be associated with early puberty,” says Danielle Buttke, a researcher at the CDC.

Buttke found that the age when a girl has her first period (menarche) has fallen over the past century from an average of age 16-17 to age 12-13, and in some cases even beginning as early as 8 or 9.

Earlier puberty isn’t just for girls. In 2012 researchers from the American Academy of Pediatrics (AAP) surveyed data on boys and found a similar trend: American boys are reaching puberty six months to two years earlier than just a few decades ago. African-American boys are starting the earliest, at around age nine, while Caucasian and Hispanics start on average at age 10.

Countless studies have been conducted on how chemicals in our foods and the products we use every day affect our chances of developing disease, but now these chemicals are being linked to early onset puberty.

Early puberty is not just a nuisance that children have to deal with earlier than ever before — it can have serious consequences to their health into adulthood.

Starting puberty early increases the chances of developing cancer and other diseases later in life, researchers have proven for the first time in recent studies.

The Telegraph reported:

Early puberty is linked to emotional and behavioral problems, along with an increased risk of diabetes, heart disease and other cardiovascular diseases, as well as cancer, later in life.

Chemicals found in food cans, nail varnish and shampoos could be triggering early puberty in girls, putting them at greater risk, and phthalates found in personal products such as deodorant, lotion and shampoo, especially those with fragrance, were related to earlier breast and pubic hair development.

Dr. Wolff said: “We believe there are certain periods of vulnerability in the development of the mammary gland, and exposure to these chemicals may influence breast cancer risk in adulthood. Exposure to these chemicals is extremely common. As such, while the association between chemicals and pubertal development seems small, the impact on the overall population is significant.”

Evidence also suggests that hundreds of compounds we use every day have “hormone disrupting” properties.

Public health professionals have known for years that chemicals like Bisphenol A (BPA), found in plastics, can mimic estrogen.

And research has also shown the dangers another class of cancer-causing estrogen-mimicking compounds: metals.

These “metalloestrogens,” like Aluminum, Mercury, Copper, Lead, and others are still present in many products despite their dangers. They have been found to increase estrogen levels in women, causing early onset puberty, and later, breast and reproductive cancers.

The Telegraph continued:

Scientists at Cambridge University have identified new genetic evidence linking the earlier onset of adolescence with several cancers known to be sensitive to sex hormones.

They found that for every one year earlier a person goes through puberty, their chances of going on to develop breast cancer increase by 6 per cent.Meanwhile, the risk rises 28 per cent for endometrial cancer, 8 per cent of for ovarian cancer and 9 per cent for prostate cancer.

It means that a girl who starts puberty at ten has a 12 per cent greater lifetime chance of breast cancer than a girl who begins as a 12-year-old.

Another factor related to the connection between chemicals and early puberty is childhood obesity.Children with a greater body mass index (BMI) have a tendency to begin puberty at an earlier age.

While teens often put on fat tissue before puberty — especially in girls, signaling the body’s ability to bear children — chemical compounds in food and the environment are also linked to obesity.

This vicious circle of chemical overload in the body and its relationship to obesity, cancers, and other diseases is alarming.

But parents can do something to avoid this cycle and its potential health hazards in their children — and they can prevent some of the danger if they start early.